Synchronizer and method of making the same



July'25,-1944. R. LAPSLEY ETAL 2,354,526

SYNCHRONIZER AND METHOD OF MAKING THE SAME Original Filed Feb. '7, 1940 2 Sheets-Sheet 1 July 25, 1944. R. LAPSLEY ETAL SYNCHRONIZER AND METHOD OF MAKING THE SAME Original Filed Feb. '7, 1940 2 Sheets-Sheet 2 mama July 25, 1944 2,354.52: SYNCHRONIZER AND METHOD OF MAKING THE SAME Robert Lapsley and Donald S. Deuce, Berrien Springs, Mich., assignors toClark Equipment Company, Buchanan, Mich, a corporation oi Michigan Original application February 7, 1940, Serial No.

Divided and this application March 3 Claims.

This invention relates to synchronizers, and more particularly is directed to synchronizers for transmissions and the like involving iriction cone rings and the method of and means for manufacturing and assembling the same on synchronizer sleeves.

This application is a division of our copending application, Serial No. 317,658, filed February 7, 1940, and relates more particularly to the synchronizer clutch structure, now Patent No; 2,319,740, issued May 18, 1943.

Heretofore, such rings have been formed from tubular stock which has been forged or otherwise shaped, and then the rings are pressed onto the receiving surfaces of the synchronizer sleeve. This has resulted in their cost being relatively high, and has also required relatively accurate fits in order to insure proper seating of the ring in the receiving recess of the sleeve.

The present invention contemplates reducing the cost of manufacture of the rings by forming them from metal blanks or strips which are cut to arcuate form and then rolled into proper form for insertion into the sleeve recesses. Such blanks or strips may be formed of a suitable ring material such as bronze sheets, or may be formed from a bi-metallic or clad metal in which a layer of bearing material is bonded to a steel base surface. When the blanks are stamped out of the sheet they are in an arcuate form with the outer are being equivalent to the circumference of the larger end of the ring and the inner are being equivalent to the circumference of the smaller end. The blanks may be provided with oil grooves all milled simultaneously by a multiple milling operation, while the blank is in a flat form whereby when the' blank is rolled into conical form the grooves are slightly dove-tailed inshape providing sharp cutting edges for the lubricant film.

Another feature of the present invention is to: simplify the blank construction so that it may. be quickly and economically formed and placed in osition. The means for securing the blank in position is particularly advantageous since it insures the ring from moving axially with respect to the seat on the synchronizer sleeve, which axial lock may be secured either by bending inwardly a small axially projecting lip on the outer end of the sleeve recess, or by bending the inner edge of the blank into the blocking recesses formed in the sleeve.

It may also be desirable under certain conditions, such as where the angularity will not insure a tight press fit, to provide for interlocking the ring and the sleeve against relative circumferential movement. This can be readily accomplished during the forming operation, since the outer circumferential edge of the flat blank may be notched during the stamping operation and such notches form interlocking keys when the lip is bent thereover.

A still further feature of the present invention resides in the heat treating of the synchronizer sleeve in such manner that a relatively soft ductile lip is left after the machining operations which produce the tapered recess. whereby this lip can be readily bent over to lock the friction ring in position.

Thus, the synchronizer assembly may be designed so that the friction rings are interlocked, both axially and circumferentially, by relatively simple means insuring proper operation of the synchronizer in a transmission construction.

Other objects and advantages of the present invention will appear more fully from the following detailed description which, taken in conJunction with the accompanying drawings, will disclose to those skilled in the art the particular construction and operation of a preferred form of the present invention.

In the drawings:

Figure 1 is a sectional view through a portion of a transmission illustrating a synchronizer embodying the present invention;

Figure 2 is a detailed view of a portion of the end of a synchronizer sleeve showing the manner in which the friction ring recess is formed;

Figure 3 is a partial perspective view showing the friction ring in position;

Figure 4 is an end elevational view of the synchronizer sleeve with the friction ring assembled therein;

Figure 5 is a detailed sectional view showing a modified manner of interlocking the friction ring and sleeve;

Figure 6 illustrates the blank from which the friction ring is formed; and

Figure 7 is a sectional view through one type of material which may be used in making the friction ring.

Referring now in detail to Figure 1, a more or less conventional type of transmission structure is shown in which the transmission case 5 has journalled therein the shaft 8 by means of bearing 1, the shaft 6 having an enlarged end 1 provided with the external gear teeth 9 adapted to mesh with the gear 9 keyed to the countershaft ID. A second gear I 2 on the countershaft 10 is adapted to have meshing engagement with a gear ll rotatably iournalled as by the needle ference of the larger end of the cone ring and having inner arcs equivalent to the inner circumference of the cone ring. Such blanks are I subjected while in the flat formto a multiple milling operation which provides a plurality of parallel grooves 55 in the face portion thereof, which grooves are preferably rectangular in section so the clutch sleeve 22, this sleeve having external v clutch teeth 23 and 24 at opposite ends thereof.

and being provided intermediate its ends with radially extendng flnger' portions adapted to 51 extend through suitable openings 28 formedin' an enclosing synchronizer sleeve 21; I

Each of the gears 8 and I! are provided with internal clutch teeth tland 12,..respectively,

adapted to be selectivelyengaged; by the clutch that when the blank It has been rolled into coniform the defining edges of the groove, as shown clearly in Figure 3. present sharp cutting 'J edges for cutting the 011 film present on the surfaces 38 and of the gears. The stamping is accurately cut to' length so that when rolled into conical form the two ends abut in tight engagement. p oviding a ring when once pressed into the tapered'recess 42. This ring is pressed along the sleeve 22 upon axial shifting movement thereof;

along the shaft portion 20. Disposed radially outwardly of the clutch teeth lland fl thegears 8 and 13 are provided with trusts-conical surfaces J} and 34, respectively, adapted.to ;be engaged by friction rings 35 and 36, respectively, carried by the Y synchronizer sleeve 21. a p I I The main elements of the synchronizer construction, insofar as its blocking action. and cooperative relatlonbetween the sleeve and clutch portions is concerned, isvdisclosed in detail in thecopending application of LeoA. Bixby and Robert Lapsley, Serial No. 298,391, filed October 7,

1939, now Patent No. 2,256,308, issued September 16, 194i. Thepresent invention more particularly is concerned with the manner in which the rings and 38 are formed and the means by which they are secured within the frusto-conical recesses in the ends of the sleeve 21.

Considering these features of the invention more in detail, the sleeve 21 is preferably subjected to a carburizing treatment in which it is packed in carbon and heated in a conventional manner to provide a depth of case substantially as shown by the layer 40 of case materialshown in Figure 2. This material is removed at the ends of the sleeve along the dotted line indicated at 42,

providing the frusto-conical recessed surface 43 and the axially projecting lip M. The surface 43 is of thesame angled inclination as the surfaces 33 and 34 of the-gears. 8 and 13, but is radially enlarged so as to provide for the introduction of the friction ring carried by the synchronizer sleeve and adapted, upon initial movement of the clutch yoke 3| shown in Figure 1, to bear against the respective surfaces 33 and 34 to bring the selected gear and clutch to substantially synchronous relationship before the final clutching movement, whereby the clutch sleeve 22 is moved into meshing engagement with the associated gear.

The friction ring .50 adapted to be received on the surface 43 is preferably formed from .flat plate, such as bronze sheets or the like, or it may be formed from clad material such as shown in Figure 7 in which the base 52 is formed of mild steel, for example, and has a layer of bearing material 53 bonded thereto to form an integral union of the two materials and provide a, sheet having a substantially uniform thickness of bearing material bonded thereon. It is apparent that either type of ring may be employed in any of the assemblies shown in Figures 1 to 6, inclusive.

Sheets of either of these types are then subiected to a stamping operation in which arcuate tapered seat until a tight press fit is obtained.

the dimensions being controlled so that the rin at no time moves inwardly into engagement with the radialshoulder ll. -When the ring has thus -beenl)r SS.edintoaposition, the outer end of the axiaLlip .is spun radially inwardly over the outerend or large diameter end of the ring, as shown at '80 in Figure 1,- thereby locking the rin against outward axial displacement. Depending upon the angularity desired on the friction surfaces, it may be desired in some cases to provide a circumferential interlocking between the ring andthe synchronizer sleeve as well as the axial lock. For such purposes, the blank 50 shown in Figurefi may be stamped with spaced notches 62 formed in the large diameter edge having an outer are equivalent to the circumoperation which bends over the lip 44 into engagement around the outer end of the ring 50 may then also provide for indentation of the lip into the notches '62 as shown at 63 in Figure 3, thereby providing a circumferential interlock preventing relative circumferential displacement between the ring and the. synchronizer sleeve. Such a construction is shown in end elevation with portions broken awa in Figure 4, and it will. be at once apparent that with such a construction, both axial and circumferential movement of thering relative to ,the synchronizer sleeveisprevented.

, An optional method of locking the ring 50 in positionon the synchronizer sleeve 21 is illustrated in Figure 5, in which it will be noted that under-cut grooves I0 are provided in the internal surface 'of the synchronizer sleeve adjacent the finger openings 26. The inner or small end of the ring 50 in this form of the invention is bent into such grooves which extend circumferentially between the openings 28, and at the openings the inner end of the ring is bent inwardly as shown at 12 to provide the circumferential interlock, the axial interlock being provided by the radially inwardly bent portions 13 intermediate the openings 26. Thus, in this form of the invention, the same type of axial and circumferential interlock is produced, but the inner end of the ring is employed for this purpose'in place of the outer end of the ring. This eliminates the necessity for the machining operations to cut off the excess materials along the dotted line 42 of Figure 2 as the synchronizer sleeve may be carburized and no further machining except for the surface 43 need b provided.

If desired, the modification shown in Figure 5 can be varied, for the sake of economy, by eliminating the undercut groove Ill and merely bending the lip or edge 12 radially outwardly over the being bent radially over the end of said ring to defining ends of openings 26 to hold the ring ll against axial outward displacement. In such case, the abutment of the bent lips 12 againstthe side walls of the openings 25 will hold the ring against circumferential displacement.

It is therefore believed apparent that we have provided a novel method of forming the friction rings from flat material and simultaneously providing the proper dimensional relationships and interlocking notches in the blanks in a single stamping operation. Such rings when produced are the equivalent of the forged rings previously employed, and have the advantage of greatly reduced cost of manufacture as well as facilitating the formation of the oil grooves therein.

In addition, it will be apparent that the novel type of means for locking the rings in position relative to the synchronizer-sleeves is of great advantage in cases where either axial locking is required or where both axial and circumferential locking of the ring to the sleeve is necessary.

We are aware that various changes may be made in certain details of the present invention without, however, departing from the underlying principles thereof, and we therefore do not intend to be limited except as defined by the scope and spirit of the appended claims.

We claim:

l. A synchronizer sleeve having a frusto-conical recess in one end thereof and an axially projecting lip overhanging the end of said recess, and a friction ring pressed into seating engagespaced notches inthe outer end thereof, said lip hold said ring against axial displacement and having portionsthereof axially indented into said notches to hold said ring against circumferential movement.

2. In combination, a synchronizer sleeve having frusto-conical recesses formed in opposite ends thereof, integral axially projecting annular flanges overlying the outer ends of said recesses, friction rings pressed into each of said recesses and having the larger ends thereof provided with circumferentially spaced notches, said flanges being forced radially inwardly over said ends of said rings to lock said rings against axial movement and having portions thereof axially indented into said notches to lock said rings against circumferential movement relative to said sleeve.

3. In combination, a synchronizer sleeve having a frusto-conical recess in one end thereof and an overhanging peripheral flange, a friction ring of frusto-conlcal form' adapted to be pressed into said recess and having its outer peripheral tive axial or circumferential displacement com- ROBERT LAPSLEY: DONALD 8. DENCE. 

